The mad scientists of Blizzard

The methods behind sound in video games, explained

Senior sound designer Chris Kowalski arrived at the Aliso and Wood Canyons Regional Park with two Blizzard team members and a duffel bag in tow. The bag barely contained its bizarre contents, and it certainly couldn’t conceal them: swords, sticks, tubes and poles jutting out at every angle. The guys would need them all.

About a mile into the park, Kowalski and his co-workers found the area they were looking for. Quiet and free from the clutters of traffic noise or people, it offered the kind of big, open space where you could swing a large object — say, a sword — and get a nice "whoosh" sound.

The trio had been recording for about an hour when a park ranger crashed their session. Kowalski, his co-workers and their swords were asked to leave.

That marked the only time Kowalski has ever been kicked out while on a job. This includes his unorthodox trips to places like Home Depot; before the Aliso excursion, Kowalski was there too, swinging around tubes in an aisle while his buddy kept an eye out for workers.

Sound design in practice is a bizarre job. It combines an ear for the tiniest of noises and a knack for experimentation with a list of required technical skills. Occasionally, it gets a little dangerous, albeit not in the life-threatening way. But to hear a sound designer explain their job is to fall in love, just a little, with the possibility that you've chosen the wrong career path.

"We're like mad scientists," Kowalski says.


Weird science

Blizzard's campus in Irvine, California, is a multi-building, labyrinthine compound, where a newcomer can easily lose their way going to the bathroom. Nestled into one of these buildings is a nondescript room where the sound team comes to capture noises. In addition to computers and recording equipment, the area houses more peculiar tools: plungers, a collection of medieval-looking weapons, some rubber chickens and many other things too strange to recognize on sight.

Today, it's a place where Kowalski and his cohort, senior sound designer Pedro Seminario, are teaching me how to tinker with foil and plastic foam. Between the two of them, their experiences encompass work on World of Warcraft, StarCraft, Hearthstone and Heroes of the Storm.

The sound effects in Blizzard's video games come from just about anywhere you can imagine: mud, cabbage, animals and — in one case — a plastic bag of stray Lego in Seminario's desk drawer. After a sound is captured, it's edited or layered with other effects, or both, to fit whatever the designer needs. Occasionally, it's stored in the team's library for later use; this is especially important, as sound designers will decide what to record and combine based on what they already have.

Rubbing two pieces of foam together — frantically, and with a good amount of muscle — is how a sound designer might re-create the sound of electricity or, for the Star Wars nerds, force lightning. Seminario coaches me through the process, exclaiming, "That's rad, dude!" or "Do one like that again!" as I work. Visually, this translates to haphazardly grating two pieces of foam together. The raw audio doesn't seem much better to me. It ekes out as cringeworthy synthetic squeals that Seminario assures me can all be captured.

"Think of it, in your head, like the classic wire dripping down from the ceiling making a spark, like 'feschew! feschew!'" he says.

If Kowalski and Seminario are any indication, sound producers are keen on their onomatopoeia.

When I pause to consider the mess I'm making — foam chips flying left and right like a tiny snowstorm — Seminario repeats that it's part of the process. "It's all about mistakes and mess-ups," he says.

"Dude. I've gotta get that again."

"A lot goes into making certain sounds sound a certain way, that you'd take the smallest and most commonplace items and turn them into something larger than life," Seminario explains. "That's what makes it continually exciting and fun ... somebody trips over something and it sounds awesome. And you're like, 'Dude. I've gotta get that again.'"

Next up is aluminum foil, a material for some textural sound. I'm warned beforehand that neither team member is positive that this will get us the best results. The point is to experiment. After I've crinkled and crunched for a few minutes, the recording session is over. Kowalski takes my recordings and plugs them into a nearby computer.

Sound designers at Blizzard use programs such as Reaper, Waves, Reaktor, Pro Tools and Sound Forge to play with and create desired effects. For my efforts, Kowalski boots up Ableton Live software and uses a custom circular Doppler, which simulates frequency changes associated with a Doppler effect, for edits. To my untrained eye, it looks like an abstract video game: a ball orbiting a circle, waiting for you to click. The sound you get changes depending on when you act. To my surprise, Kowalski and Seminario are right about my feeble efforts. Combined and mixed with various pitches and speeds, the foil and foam are transformed into something like a laser gun, sizzling into unseen targets with a satisfying, electric buzz.

The process in this case is a quick one, but finishing a single sound is a subjective science. Seminario says that while he can wrap up a sound within the day, the determining factors are varied: voice-over work, a need for specific tools and so on. Seminario likens the process to cooking: It's all about taste.

"What really defines a good sound?" he says. "It's so [subjective]. What you might find good, somebody else might not. It's like the common perspective that enough people agree on it, so therefore it's good."

Pedro Seminario's favorite sounds

Seminario doesn't hesitate when you ask which games he admires for their sound.

"Call of Duty: Advanced Warfare," he says. "Holy crap."

It's the game's explosions that make Seminario swoon, as well as the general level of detail given to its audio. Seminario jokes that the team at Blizzard comes up with "stupid terms" for sounds all the time, in this case praising Advanced Warfare's "punchinator."

"Yeah, that game has got the punchinator," Kowalski seconds.

Batman: Arkham Knight is another game Seminario name-checks for its personality, but he's interested in the sounds of indie games, too.

"What speaks to me personally is character," he says. "Personality. If it's not the greatest-sounding game ever, but maybe there's some cool sounds in there, it's like, 'Man, that's really evocative and really cool.'"

Kowalski's favorite sounds to make, for example, might also be the grossest. The designer delights in squishy effects familiar to gore or horror. In a more lighthearted, action-based game like Heroes of the Storm — Blizzard's mashup MOBA — these effects are subtle, acting more as an atmospheric appetizer than a table-setter.

Take the battleground called Tomb of the Spider Queen, for example. Kowalski and Seminario explain the process in detail. Start with a trip to Home Depot (a beginning point that comes up frequently) and purchase the thickest, most industrial soap you can find. Drip or pour the soap through a funnel, and use hand plungers to squish and smear it around. Record and repeat as needed.

The raw audio sounds ... wet. It's a series of gooey, sloppy fart sounds you'd blame on a cartoon goblin. In-game, it's refined to background noise that bubbles up between the wallops and whoops of fighting heroes.

Gore, as with destruction, impact or animal sounds, is always in high demand. You can never have enough of certain elements, says Seminario, who again falls back on his cooking analogy.

"You're constantly hunting to find fresh ingredients," he says. "Because if not, you feel like you're just getting the same stuff over and over again instead of keeping it fresh and keeping it interesting. You try to get new elements."

Another experiment to get bubble and squish sounds led the team to hunt down crafting clay. With a little water and a few Ghost reenactments, the team recorded clicks and pops to play with.

"As we were recording it," Kowalski says, "we were like, 'Ugh, this is a wash, this is terrible.' And then we get it back and we're just like, 'Oh my god, this stuff's amazing.'"

Kowalski and Seminario tell their field stories often and with enthusiasm, so much so that it's easy to forget the technical aspect of their job. Seminario is quick to reinforce the importance of time budgeting and prompt editing.

"If you don't edit stuff right away," he says, "it'll just kind of sit there unedited for awhile and you get other stuff that comes in, and you forget about it. Like, I had this perfect sound that we recorded at this one thing, and then you're like, 'Wait, what did I call it? Where was it? Oh god, why?'"

Kowalski echoes this. Your sensibilities may change from day to day, and your initial inspirational spark may fade, he says. To let a sound sit is to let it lose its power.

"You're still kind of running on the emotions that you have from the actual recording session," he says of same-day editing. "How it made you feel. That excitement."

heroes of the storm

Stop, collaborate and listen

Asked if he has a background in engineering or science, Seminario laughs.

"I mean, science fiction," he says.

The skills that sound designers use are specialized, but not exclusive to those with serious schooling in the matter. Seminario was never a good student. He describes himself as someone who barely got through high school; he attended recording engineering school a few years after graduating. Kowalski, meanwhile, studied marketing and psychology in college. Kowalski credits his interest as being tied to music, while Seminario took interest in the business of sound design. What sounds cool, and what doesn't. Learning from your peers.

The community is a friendly one, he says, eager to share and learn techniques and tools from each other. The makers of Mortal Kombat X, for example, used the same yellow hand plungers for their game's fatalities that Blizzard co-opted for its Tomb of the Spider Queen effects.

"Do you have, like, a meth lab or something?"

"We literally did it the day before we saw the Mortal Kombat article on Polygon's site," Seminario says.

Also common to the sound designer hive mind? Dry ice, according to Seminario and Kowalski. Running dry ice along certain kinds of metal will — because of a rapid temperature change — cause it to screech and sing. A neat trick that anyone outside of sound design circles might not be as familiar with.

"It's fun to go and buy it, too, because whenever you go to the grocery store and you ask them for dry ice, they always give you a weird look," he adds. In working on World of Warcraft's Warlords of Draenor expansion, Kowalski needed Iron Horde sounds; he ran to a local store to pick up a few blocks of dry ice. The associate who helped him was suspicious.

"He's like, 'What are you doing with all this dry ice?'" Kowalski says. "'Do you have, like, a meth lab or something?'

"I'm like, 'What? No, dude. We're making sounds with them.'"

Chris Kowalski's favorite sounds

Kowalski, a father of two, spends a lot of time playing kids games at home. He drops this fact before explaining his choice: Nintendo's 2015 paint shooter, Splatoon, a game filled with character and personality he greatly admires.

"It's just really fun playing it with my son," he says. "Things don't have to be super groundbreaking. It's just how they make you feel and is there satisfaction there."

He likens it to a common refrain in entertainment: that sound can play the role of a new character.

"You're giving it emotional space and that's the number one important thing."

Within Blizzard, there's a friendly sense of competition among the various sound teams. Seminario compares it to the houses in Harry Potter — score a good sound and get 20 points.

"It's all good-natured," he says. "It's a very collaborative learning environment. If you talk about the greatest natural resource that we have in the sound department, [it's] personnel. The people. The knowledge and experience, life experience that they have ... what you choose to highlight, and what you choose to put in there."

Sound design is the sum of its parts. It's more than just the the singular boom of an explosion, for example.

"Adding that 'sch-boommm,' or like, 'boom tch tch' — those extra little things help carry and give it that character and personality and make it memorable," Kowalski says. "I think that's the thing that we're always striving to do. Do you remember the sounds? Growing up, the old-school console games and things like that, everybody knows all the sounds from Mario. They're just ingrained in your head.

"With modern sound design, we are becoming more visceral. We have more technology, and so sometimes because the technology back then was more synth-based, how do you make things memorable that aren't so musical?"

blizzard sound team
A few members of Blizzard's sound team, left to right: Chris Kowalski, Colton Carmine, Shawn Minoux, Pedro Seminario, Glenn Stafford

Sound designers have to get into their players' heads. They need to understand their expectations within the game's context and without. They need to have empathy, Seminario says.

"If you can understand what other people are feeling, you can make them feel what they want to feel, and audio is all about feels," he says. "Your perspective and your ability to choose one sound over another is your voice in sound design; it's like your fingers on the neck of a guitar that shape your tone as a guitar player.

He points to the combination of beloved Blizzard characters in Heroes of the Storm. Respecting where these characters come from, and how they might sound in this new game, is respecting how players feel.

"It's like kind of putting yourself in the shoes of somebody else," Seminario says. "Trying to at least have hints of that in there so that you can do right by the fans.

heroes of the storm

Success, failure and the dangers in between

Sound production is an active job. It demands hands-on work where things can get ... well, not exactly perilous, but the word "hazardous" is thrown around often.

In creating Heroes of the Storm's Murky Pufferfish, Kowalski recalls accidentally terrorizing a few of Blizzard's employees. The senior sound designer purchased a bundle of balloons, filled them to the bursting point with a plug-in compressor and stashed them in a meeting room. His goal was to capture a textural sound, a rub that could simulate puffer fish expansion. Instead, he effectively created a room of colorful grenades. A few stray balloons remained afterward, where they'd explode without warning. It was not the most popular room.

"You'd go back and be like, 'Alright, let's talk about this one feature we're gonna do,' and then one of them just pops, scares the crap out of everyone," Seminario says. "'Ahhh, I was just sitting there.'"

Kowalski himself had a small scare during the process.

"when you shoot them, they blow up. They sell this stuff."

"I picked up one of the balloons, and it literally exploded right next to my ear," he says. "My ear was ringing for like 45 minutes straight. I was like, 'Oh my god, I'm gonna lose my hearing.'"

He did not. As Seminario very cheerfully explains, things go wrong all the time. In the case of the foam and foil, those items were chosen for being "somewhat clean and nondangerous." Contrast this with just one of Seminario's experiences, in which he recorded binary explosives.

"They're completely neutral when you have them," he says. "But when you shoot them, they blow up."

Seminario pauses. "They sell this stuff," he says.

"Sometimes you have to put yourself in harm's way to get certain sounds. We've recorded tools and stuff like that that are pretty dangerous ... Sometimes the dumbest stuff happens, and you get hurt, and you've just got to deal with it. You've just got to learn to be careful. Keeping an ear open to what somebody else might be trying to tell you."


Seminario has a few stories about hurting himself, like the time he had a run-in with an arc welder at his in-laws' house. Dry ice, a mostly safe material, must be handled with gloves, or it will stick to bare skin with a painful tenacity.

(Kowalski interjects to offer a comparison about skin loss: "It's like mozzarella.")

In Seminario's experience, however, designers are more prone to damaging equipment. Or clothing.

"My wife refuses to do my laundry forever now," he says. "Because the last time we did the clay stuff, I had clay up to half my leg."

Mistakes, and even failures, happen all the time. Sounds come out differently than you'd expect, he says, or they just don't feel right. When you involve another independent party — like an animal — it gets even harder.

"It especially sucks to go to the trouble to make an appointment with somebody," Seminario says. "'I want to go out there and record your finest hawk, sir.'

"Sometimes the animals just don't say anything. In the '70s and '80s, I think there were special tricks that you could get animals to talk — not having to do with drugs — but having to do with cigarette smoke, which is totally cruel. If you were to smoke downwind of an animal, it would make it emote and do vocalizations."

"I want to go out there and record your finest hawk, sir."

The most difficult sounds to make are also the smallest: user interface sounds, tiny clicks or beeps and boops that players will hear over and over again.

"Holy crap," says Seminario. "Super hard. You have to tell the entirety of an emotion in one-thirty-second of a second.

"Making those clicks and those transitions from one place to another can be really, really difficult because you just don't have any time to do anything. And if you get those sounds wrong, it's immediately noticeable."

A failure in the moment can still lead to something productive in the future. You learn from it. Maybe you even recycle some of it for later. Knowing the difference between something that does work, and something that might work later, is important.

In other words: experimentation, experimentation, experimentation. To be a sound designer is to fail, Seminario says, and to fail often. Studying sound professionally won't guarantee you'll be a natural fit for the job.

"A lot of really good sound designers are self-taught," he says, comparing them to musicians. "I suppose school is what you make of it."

Seminario's advice for budding designers is varied, from the obvious (play games) to the technical (make a sizzle reel). It helps to record everything and edit sounds right away; to trust your instincts and to respect yourself and others in the space. Perhaps his most important advice is also the simplest: "Persevere, and don't give up. Sometimes you will fail, too."

"An expert is — hold on, there's a quote that I just read the other day — an expert is one who's made all of the mistakes already," he says. "I think that's right. Give or take a few words." Babykayak